Amgen v TKT: Assessment of inventive concept is crucial for assessing infringement of biotechnology patents

Abstract

In a landmark decision, the House of Lords in Kirin Amgen v Hoechst & TKT has confirmed the correct approach of proper construction of patent claims, as interpreted in the full light of the invention, to assess infringement. There is no 'doctrine of equivalence' under English law: variants falling outside a patent claim cannot infringe that claim, even if they are somehow 'equivalent' to the claimed invention.